¿Qué es este código add_to_serializer en todos estos plugins?

Desarrollador
1

I have seen this code in discourse_signatures plugin

User.register_custom_field_type('see_signatures', :boolean)
User.register_custom_field_type('signature_url', :text)
User.register_custom_field_type('signature_raw', :text)

if SiteSetting.signatures_enabled then
  add_to_serializer(:post, :user_signature, false) {
    if SiteSetting.signatures_advanced_mode then
      object.user.custom_fields['signature_raw']
    else
      object.user.custom_fields['signature_url']
    end
  }

  # I guess this should be the default @ discourse. PR maybe?
  add_to_serializer(:user, :custom_fields, false) {
    if object.custom_fields == nil then
      {}
    else
      object.custom_fields
    end
  }
end

In discourse national flags plugin

User.register_custom_field_type('nationalflag_iso', :text)

if SiteSetting.nationalflag_enabled then
  byebug;
  add_to_serializer(:post, :user_signature, false) {
    object.user.custom_fields['nationalflag_iso']
  }
  byebug;
  # I guess this should be the default @ discourse. PR maybe?
  add_to_serializer(:user, :custom_fields, false) {
    if object.custom_fields == nil then
      {}
    else
      object.custom_fields
    end
  }
end

I am not able to understand what is add_to_serializer is doing.

I checked in def add_to_serializer

def add_to_serializer(serializer, attr, define_include_method=true, &block)
  klass = "#{serializer.to_s.classify}Serializer".constantize rescue "#{serializer.to_s}Serializer".constantize

  klass.attributes(attr) unless attr.to_s.start_with?("include_")

  klass.send(:define_method, attr, &block)

  return unless define_include_method

  # Don't include serialized methods if the plugin is disabled
  plugin = self
  klass.send(:define_method, "include_#{attr}?") { plugin.enabled? }
end

I understand that User.register_custom_field_type('signature_raw', :text) will register a custom field type to User object. But what is add_to_serializer doing? I am not able to understand, can you explain me in plain english?

2 Me gusta
2

It’s essentially adding to the information that Discourse serializes out when sending that model to the client. For example, you may see a request to this endpoint when loading up a topic page:

http://meta.discourse.org/t/2349082394.json

which returns some payload like this:

{
  title: "Some topic title",
  archetype: 'regular',
  category_id: 7,
  post_stream: { posts: [...] },
  posts_count: 15,
  (etc etc.. lots more info about the topic in question)
}

Which is the json representation of a Discourse topic.

If I want to know more about the topic because of additional ‘stuff’ I do in my plugin, I can put in a line like

add_to_serializer :topic, :flag_name do
  object.flag_name # <- NB that 'object' here is the topic being serialized
end

(Also, by default, this method simply sends the specified message to ‘object’, meaning that

add_to_serializer :topic, :flag_name

is the same as

add_to_serializer :topic, :flag_name do
  object.flag_name
end

)

Once I’ve added the method to the serializer, I can end up with JSON output which includes that additional info

{
  title: "Some topic title",
  archetype: 'regular',
  category_id: 7,
  post_stream: { posts: [...] },
  posts_count: 15,
  flag_name: "some flag name"
  ...
}

Also note that you could achieve the same thing by overwriting the TopicSerializer class (which is exactly what the code snippet you’ve provided is doing)

# plugin.rb
TopicSerializer.class_eval do
  attributes :flag_name
  def flag_name
    object.flag_name
  end
end
20 Me gusta
4

Hi,
When running the following code,

TopicSerializer.class_eval do
  attributes :flag_name
  def flag_name
    object.flag_name
  end
end

I was getting the error “block in activate!’: uninitialized constant TopicSerializer (NameError)”. I think I have to “import” or “require” the TopicSerializer dependency. Can you please tell me what would be the dependency, as I am not able to figure it out.

1 me gusta
5

Add this directly above your code require_dependency 'topic_serializer'

require_dependency 'topic_serializer'
class ::TopicSerializer
  attributes :flag_name
  def flag_name
    object.flag_name
  end
end
1 me gusta
6

Hi thanks, but I got the error " `load’: No such file to load – topic_serializer (LoadError)". Does it pull from the app/serializers folder? I checked in that folder, I could find topic_list_serializer.rb, and many other related to topic, but couldnt find topic_serializer.rb

1 me gusta
7

Right! Try TopicViewSerializer.

require_dependency 'topic_view_serializer'
class ::TopicViewSerializer
  attributes :flag_name
  def flag_name
    object.flag_name
  end
end
5 Me gusta
8

Heyy, I have added a custom field to my category edit box.

When I submit the form, I can see something these fields are submitted in the js console
custom_fields[default_tag][]:good-feedback custom_fields[default_tag][]:one-more-tag

in my main plugin file, I am doing

add_to_serializer(:basic_category, :default_tag){object.custom_fields[“default_tag”]}

My custom fields aren’t getting saved to the db.

9

does doing:

add_to_serializer(:basic_category, :default_tag, false ){object.custom_fields[“default_tag”]}

now work?

11

I had solved it that time by adding a function on :before_action event and converted the array to a delimited string and vice versa while retrieving.

I didn’t actually dig into why an array couldn’t be stored as custom field out of the box.

1 me gusta
12

So this might streamline the code potentially?

13

Yes it would if it worked in this case. I’ll try this in sometime and get back to you.

1 me gusta
14

Poor you that must’ve been painful at the time :wink:

1 me gusta
15

It was a sunday evening and curiosity took over. It was somewhat painful but fun.
It was something that @pfaffman was trying to do.

No pain no gain :wink:

1 me gusta
16

haha, so true! …

1 me gusta
17

Hola, tengo el mismo problema (los custom_fields se envían en la consola de JS, pero no se guardan en la base de datos). Utilicé el método add_to_serializer(:basic_category, :default_tag, false ){object.custom_fields["default_tag"]} en mi archivo principal del plugin.

¿Sigue siendo recomendable esta solución?

1 me gusta
18

Hay muchas preguntas surgiendo aquí. ¿Campos personalizados de qué, en primer lugar?

19

Estoy trabajando en un plugin para automatizar la sincronización de grupos de Discourse con LDAP. Agregué un campo personalizado al modelo Group (ldap_dn) para guardar el nombre del grupo LDAP. Estoy intentando recuperar el valor del campo personalizado desde un campo de entrada que agregué en el plugin-outlet de membresía y guardarlo en la base de datos para usarlo más tarde.

Para ello, agregué lo siguiente a mi archivo plugin.rb:

Group.register_custom_field_type(‘ldap_dn’, :text)
Group.preload_custom_fields << “ldap_dn” if
Group.respond_to? :preloaded_custom_fields

if SiteSetting.groups_sync_enabled then
add_to_serializer(:group_show, :custom_fields, false) {
object.custom_fields
}
end

Soy nuevo en Rails y Ember, así que no estoy seguro de si debo realizar otro paso para guardar los custom_fields en la base de datos o dónde radica el problema.

1 me gusta
20

Creo que si agregas
register_editable_group_custom_field 'field_name'
en tu plugin.rb

eso debería resolver el problema.

Nota:
El serializer se utiliza para enviar los datos al cliente, no para recibirlos.

1 me gusta
21

¡Ah, vale! Soy nuevo, así que esta pregunta puede parecer muy obvia, pero ¿para recibir los datos, lo hago a través de la API?

1 me gusta
22

Mi solución dará luz verde a tu campo cuando llegue al servidor. Así que se trata de recibir los datos.

1 me gusta